ENME 351 Electronics and Instrumentation II
Homework 4: ADCs, Sampling, and Aliasing
Due Thursday, Sept 29 by 11:59PM as a single PDF or images to Gradescope
*Include your name and date on each assignment and draw a box around your answers.
1. Using the ATmega328P (the microcontroller on your Arduino) datasheet, answer the following
questions about its ADC.
a. What type of ADC is it? Successive Approximation Register ADC (p. 250)
b. What is the ADC resolution? 10-bit (p. 250)
c. What is the absolute accuracy in volts for a 5V supply? +/- 2 LSB (p. 250)
VLSB = (5 V)/210 = 4.88 mV, absolute accuracy is +/- 9.77 mV
d. What is the maximum number of samples that can be taken per second at maximum resolution?
15000 Samples/sec at maximum resolution (p. 250)
2. A 0 to 3 V, 10-bit ADC is used to measure an input voltage of 1.225 V.
a. Determine the binary representation and the analog value approximation of the input signal.
b. If we wanted to ensure that the analog approximation is within 1 mV of the actual input voltage,
how many bits would we require in the ADC?
3. You would like to use a 16-bit ADC to sample and digitally store some music records you dug up at
your parents’ (maybe grandparents’?) house. If the ADC is capable of sampling up to 50 kSamples/s,
a. What is the minimum time required for each sample conversion?
Homework 4 Page 1 of 3 Prof. Bergbreiter
This study source was downloaded by 100000850872992 from CourseHero.com on 02-21-2023 20:58:50 GMT -06:00
https://www.coursehero.com/file/17423100/hw4sol/
Homework 4: ADCs, Sampling, and Aliasing
Due Thursday, Sept 29 by 11:59PM as a single PDF or images to Gradescope
*Include your name and date on each assignment and draw a box around your answers.
1. Using the ATmega328P (the microcontroller on your Arduino) datasheet, answer the following
questions about its ADC.
a. What type of ADC is it? Successive Approximation Register ADC (p. 250)
b. What is the ADC resolution? 10-bit (p. 250)
c. What is the absolute accuracy in volts for a 5V supply? +/- 2 LSB (p. 250)
VLSB = (5 V)/210 = 4.88 mV, absolute accuracy is +/- 9.77 mV
d. What is the maximum number of samples that can be taken per second at maximum resolution?
15000 Samples/sec at maximum resolution (p. 250)
2. A 0 to 3 V, 10-bit ADC is used to measure an input voltage of 1.225 V.
a. Determine the binary representation and the analog value approximation of the input signal.
b. If we wanted to ensure that the analog approximation is within 1 mV of the actual input voltage,
how many bits would we require in the ADC?
3. You would like to use a 16-bit ADC to sample and digitally store some music records you dug up at
your parents’ (maybe grandparents’?) house. If the ADC is capable of sampling up to 50 kSamples/s,
a. What is the minimum time required for each sample conversion?
Homework 4 Page 1 of 3 Prof. Bergbreiter
This study source was downloaded by 100000850872992 from CourseHero.com on 02-21-2023 20:58:50 GMT -06:00
https://www.coursehero.com/file/17423100/hw4sol/
